Stopped and control delay at signalized intersections

This document discusses an investigation into the relationship between stopped and control delay for through lane groups at actuated signalized intersections. The research was motivated by potential inconsistencies in the level-of-service thresholds between the 1994 and 1997 Highway Capacity Manuals. The research identified four existing analytical models that describe the stopped to control delay relationship, Reilly-Gardner, Akcelik, Teply, and Quigora-Bullock.; The research also identified five variables as having an impact on the stopped to control delay relationship, namely the delay magnitude, controller type, number of lanes, percent split, and approach speed. Focusing on actuated controllers, a comprehensive simulation-based dataset was developed using CORSIM that allowed for direct comparison of the existing analytical models noted above. None of the four models proved capable of describing all the factors that affect the stopped to control delay relationship. The CORSIM dataset was also used to test the consistency of the 1994 and 1997 level-of-service thresholds, which were found to be inconsistent. Using control delay and the 1997 thresholds tended toward a worse level-of-service than using stopped delay with the 1994 thresholds.; Using the same CORSIM dataset, three new analytical models describing the stopped to control delay relationship were developed. Both the existing and the newly developed analytical models were validated using field data. The validation steps showed that one of the newly developed models, called the Multivariate-Linear Model, provided the best overall description of the stopped to control delay relationship. This model was used to develop a new set of level-of-service thresholds for use with control delay. This new set of thresholds was shown to be more consistent with the 1994 Highway Capacity Manual stopped delay thresholds than the 1997 Highway Capacity Manual control delay thresholds.